The present invention relates to an organopolysiloxane composition for the formation of a release film, and, more particularly, relates to such a composition which evidences a rapid curing rate at low temperatures (not exceeding 100 degrees Centigrade) and which develops an extremely good release performance against tacky substances.
It is well known that such properties as water repellency, slickness, releaseability from tacky substances, and the like, can be generated by forming a cured film from an organopolysiloxane composition on the surface of various substrates, for example, various types of paper, laminated paper, synthetic films, knitted or woven fabrics, metal foils, etc. For example, Japanese Patent Publication Number 52-40918 discloses an organopolysiloxane composition comprising vinyl-containing organopolysiloxane, organohydrogenpolysiloxane, and platinum-type compound, while Japanese Patent Application Laid Open (Kokai) Number 62-86061 (86,061/87) discloses an organopolysiloxane composition comprising platinum-type compound, organohydrogenpolysiloxane, and low-viscosity organopolysiloxane possessing higher alkenyl groups such as the hexenyl group.
However, the former organopolysiloxane composition has a slow curing rate, and, in order to induce its curing in a short period of time, it becomes necessary to implement a high-temperature heat treatment on the level of at least 140 degrees Centigrade. This causes such problems as heat shrinkage and blistering in the substrate as well as a decline in gloss by mirror-finish.RTM.d surfaces. In the case of the latter organopolysiloxane composition, while the curing rate is in fact rapid, this composition is not entirely satisfactory in its applications due to a somewhat inferior release performance.